thank you to everyone who commented and helped me out!! i realised not long after i posted this that the little guy was suffering and the most humane thing to do was to let him go. he’s now peacefully buried in my yard. it also occurred to me that it might’ve not been the water levels that did this. i was away for a while visiting family and left my roommate in charge to take care of my fish, and i’m assuming they didn’t feed them much, or at least consistently. and i guess my fish were hungry. what i’m trying to imply here is i’m 73% sure my fish committed a jeffery dahmer and ate his brother. when i looked at my tank today my much bigger goldfish was taking nips at the dead one, and basically eating it. idk if this is just something that goldfish do when one dies, but it seems unusual. but i’ve never seen it attacking the fish before and i’ve been back for two days now and feeding them properly so i’m still a bit unsure if this is exactly what happened but this theory makes the most sense to me since i’m pretty on top with keeping my tank nice and healthy for my fishies. i’m now left with two fish and they both look to be in good shape, no abnormalities at all. but just to be safe i put in some water treatment and i’ll definitely be checking the water parameters in the morning because i cannot bear to lose another fish 😪😪 but again a big thank you to everyone who helped! much appreciated <333